Lipidox is a Swedish company having its roots in the Karolinska Institute, Stockholm. We carry out customer-initiated synthesis of unusual fatty acids for use as standards and substrates in biomedical research. Fatty acids so far prepared are given in the Fatty Acid List. Uncommon monoenoic and polyunsaturated structures, odd-numbered polyunsaturated fatty acids, branched-chain saturated fatty acids as well as certain deuterium-labeled fatty acids are included. In addition, a number of oxygenated fatty acids belonging to the oxylipin family of compounds are listed. Many of these compounds are available in stock, whereas others are prepared upon request.
Methodologies used for preparation include total synthesis using acetylenic or Wittig couplings, chemical modifications of existing fatty acids, and isolation of uncommon fatty acids from seed oils. The majority of these materials is not available from other commercial sources.
For more information or to receive a quotation for custom synthesis, please refer to the Contact page.
Fatty acids are organic compounds having the general formula R-COOH. Structural and geometrical isomerism of the alkyl chain can theoretically lead to myriads of different structures. However, fatty acids from biological sources show relatively modest structural variation, a fact that can be ascribed to the specificities of the biosynthetic enzymes. Thus, unbranched acyl chains having an even number of carbon atoms are the rule, a consequence of the mechanism of biological fatty acid synthesis by successive two-carbon elongations starting from acetyl-CoA. Unsaturated fatty acids, divided in monounsaturated ones having one double bond and polyunsaturated having two or more double bonds, likewise show limited structural variation because of the specificities of the desaturase enzymes involved. Such enzymes most often introduce Z-configured double bonds at the ω3, ω6 or ω9 positions counted from the methyl end, or homoallylically to an existing double bond in the carboxyl end. Commonly occurring polyunsaturated fatty acids of the ω3, ω6 or ω9 families possess two or more copies of the Z-configured element -CH=CH-CH2- and have at least one bisallylic methylene group, -CH=CH-CH2-CH=CH-. It is the lowered carbon-hydrogen bond dissociation energy of this bisallylic methylene that makes polyunsaturated fatty acids susceptible to autoxidation and also allows enzymatic conversions by e.g. lipoxygenases, cyclooxygenases and conjugases.
Deviations from the above outlined rules, or secondary transformations of existing fatty acids, lead to the formation of various uncommon fatty acids in animals, plants and bacteria. Thus, fatty acids having an odd number of carbons can be produced by α-oxidation pathways by which existing acyl chains are shortened by one carbon atom. Branches may be introduced by alkylation of unsaturated acyl chains, such as the formation of 10-methylstearic acid (tuberculostearic acid) in tubercle bacilli by methylation of oleate by S-adenosylmethionine. Certain unorthodox fatty acid desaturases introduce double bonds in uncommon positions, e.g. the 5(Z) double bond of 5(Z),9(Z)-octadecadienoic acid (taxoleic acid), the 5(E) double bond of 5(E),9(Z),12(Z)-octadecatrienoic acid (columbinic acid), and the 6(Z) double bond of 6(Z)-hexadecenoic acid (sapienic acid). Furthermore, the recently studied conjugase type of desaturases catalyzes the dehydrogenation of polyunsaturated fatty acids into conjugated trienoic and tetraenoic acids such as α-eleostearic, punicic and parinaric acids.
5(Z),8(Z),11(Z)-Tetradecatrienoic acid (14:3) is the tetranor derivative of linolenic acid and is formed by two cycles of ß-oxidation. It is a minor fatty acid in rape (Brassica napus) oil (1) and has been detected in trace amounts in mitochondrial membranes from maize seedlings (2). Its ocurrence in snow alga (Chloromonas brevispina) (3) and in larvae and adults of mosquitoes (Diptera: Culicidae) (4) has also been established. Use of the acid as a marker of mosquito biomass in terrestrial food webs has been suggested (4).
Because of its three methylene-interrupted double bonds, 14:3 is a potential substrate for lipoxygenases, however, the results with soybean lipoxygenase was reportedly negative (5).
In recent work we re-tested 14:3 as a substrate for soybean lipoxygenase-1 (0oC, pH 10.4) and observed good conversion using a spectrophoto-metric assay. The hydroperoxide product was reduced with NaBH4 and analyzed by GC-MS following methyl-esterification and trimethylsilylation. Two products were observed, i.e. 9-hydroxy-5(Z),7(E),11(Z)-tetradeca-trienoic acid and 12-hydroxy-
5(Z),8(Z),10(E)-tetradecatrienoic acid. Thus, the enzyme can oxygenate 14:3 following abstraction of a hydrogen from either the C-7 or the C-10 carbon.
The synthetic outline of 14:3 can be found here.
1. Sebedio, JL and Ackman, AG (1979) J. Am. Oil Chem. Soc. 56, 15-21.
2. Makarenko, SP, Konstantinov, YM, Kbotimchenko, SV, Konenkina, TA and Arziev, AS (2003) Rus. J. Plant Physiol. 50, 487-491.
3. Rezanka, T, Nedbalova, L and Sigler, K (2008) Microbiol. Res. 163, 373-379.
4. Sushchik, NN, Yurchenko, YA, Gladyshev, MI, Belevich, OE, Kalachova, GS and Kolmakova, AA (2013) Insect Sci. 20, 585-600.
5. Hatanaka, A, Kajiwara, T, Matsui, K. and Ogura, M (1990) Z. Naturforsch. 45, 1161-1164.